F. Leland Russell, Svata M. Louda, Tatyana A. Rand, and Steven D. Kachman. 2007. Variation in herbivore-mediated indirect effects of an invasive plant on a native plant. Ecology 88:413–423.

Appendix G. Regression of mean number of Rhinocyllus conicus egg cases per wavyleaf thistle flower head as a function of the number of bolting native thistles within a 5-m radius of the sampled wavyleaf plant.

FIG. G1. Regression of mean number of Rhinocyllus conicus egg cases per wavyleaf thistle flower head as a function of the number of bolting native thistles within a 5-m radius of the sampled wavyleaf plant. Native thistle species include Cirsium undulatum, C. ochrocentrum, and C. flodmannii. R. conicus egg load per wavyleaf thistle flower head was not significantly related to number of bolting native thistles within 5 m, nor was there a significant interaction between distance to the focal musk thistle patch and neighbor density on egg load per flower head. Regression equations are (1) at 30–50 m: egg load per head = 0.657 + 0.0002(number of bolting native thistles), (2) at 80–100 m: egg load per head = 0.589 – 0.004(number of bolting native thistles), and (3) at 200–220 m: egg load = 0.272 – 0.013(number of bolting native thistles).